This is a note to let you know that I've just added the patch titled
PCI/PM: Do not suspend port if any subordinate device needs PME polling
to the 3.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-pm-do-not-suspend-port-if-any-subordinate-device-needs-pme-polling.patch
and it can be found in the queue-3.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From c733b77475707cc3980542c86ee0ad5c841d544c Mon Sep 17 00:00:00 2001
From: Huang Ying <[email protected]>
Date: Wed, 26 Dec 2012 10:39:23 -0700
Subject: PCI/PM: Do not suspend port if any subordinate device needs PME polling
From: Huang Ying <[email protected]>
commit c733b77475707cc3980542c86ee0ad5c841d544c upstream.
Ulrich reported that his USB3 cardreader does not work reliably when
connected to the USB3 port. It turns out that USB3 controller failed to
awaken when plugging in the USB3 cardreader. Further experiments found
that the USB3 host controller can only be awakened via polling, not via PME
interrupt. But if the PCIe port to which the USB3 host controller is
connected is suspended, we cannot poll the controller because its config
space is not accessible when the PCIe port is in a low power state.
To solve the issue, the PCIe port will not be suspended if any subordinate
device needs PME polling.
[bhelgaas: use bool consistently rather than mixing int/bool]
Reference: http://lkml.kernel.org/r/[email protected]
Reported-by: Ulrich Eckhardt <[email protected]>
Tested-by: Sarah Sharp <[email protected]>
Signed-off-by: Huang Ying <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/pci/pcie/portdrv_pci.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -134,10 +134,28 @@ static int pcie_port_runtime_resume(stru
return 0;
}
+static int pci_dev_pme_poll(struct pci_dev *pdev, void *data)
+{
+ bool *pme_poll = data;
+
+ if (pdev->pme_poll)
+ *pme_poll = true;
+ return 0;
+}
+
static int pcie_port_runtime_idle(struct device *dev)
{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ bool pme_poll = false;
+
+ /*
+ * If any subordinate device needs pme poll, we should keep
+ * the port in D0, because we need port in D0 to poll it.
+ */
+ pci_walk_bus(pdev->subordinate, pci_dev_pme_poll, &pme_poll);
/* Delay for a short while to prevent too frequent suspend/resume */
- pm_schedule_suspend(dev, 10);
+ if (!pme_poll)
+ pm_schedule_suspend(dev, 10);
return -EBUSY;
}
#else
Patches currently in stable-queue which might be from [email protected] are
queue-3.7/pci-pm-do-not-suspend-port-if-any-subordinate-device-needs-pme-polling.patch
queue-3.7/pci-pm-keep-runtime-pm-enabled-for-unbound-pci-devices.patch
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